Explains Aristotle's views on the possibility of continuous variation between biological species. While the Porphyrean/Linnean classification of species by a tree suggests species are distributed discretely, Aristotle admitted continuous variation between species among lower life forms.

In a well-known paper, Reginald Jackson expresses a sentiment not uncommon among readers of Locke: “Among the merits of Locke’s Essay…not even the friendliest critic would number consistency.”2 This unflattering opinion of Locke is reiterated by Maurice Mandelbaum: “Under no circumstances can [Locke] be counted among the clearest and most consistent of philosophers.”3 The now familiar story is that there are innumerable inconsistencies and internal problems contained in Locke’s Essay. In fact, it is probably safe to say that there is (...) not another canonical, well-respected, and seminal philosopher whose work is so widely thought to be swarming with inconsistencies. I, however, do not think that the common, unflattering view of Locke is accurate as a general view of the Essay. But despite my wishes to the contrary, I do believe that Locke’s chapter ‘Of Identity and Diversity’ (2.27)4 leads to (at least) one intractable problem, a problem that is the subject of this paper. (shrink)

While the tradition of Locke scholarship holds that both Locke and Boyle are species anti-realists, there is evidence that this interpretation is false. Specifically, there has been some recent work on Boyle showing that he is, unlike Locke, a species realist. In this paper I argue that once we see Boyle as a realist about natural species, it is plausible to read some of Locke’s most formidable anti-realist arguments as directed specifically at Boyle’s account of natural species. This is a (...) break from the tradition because no one in the literature has yet suggested that some of Locke’s arguments in Book III of the Essay include a criticism of Boyle’s doctrine of species. Moreover, identifying Boyle as Locke’s intended target illuminates some of the more vexing passages in the Essay concerning real essences. (shrink)

Locke is often cited as a precursor to contemporary natural kind realism. However, careful attention to Locke’s arguments show that he was unequivocally a conventionalist about natural kinds. To the extent that contemporary natural kind realists see themselves as following Locke, they misunderstand what he was trying to do. Locke argues that natural kinds require either dubious metaphysical commitments (e.g., to substantial forms or universals), or a question-begging version of essentialism. Contemporary natural kind realists face a similar dilemma, and should (...) not appeal to Locke in their defense. (shrink)

This paper argues that the English philosopher John Locke, who has normally been thought to have had only an amateurish interest in botany, was far more involved in the botanical science of his day than has previously been known. Through the presentation of new evidence deriving from Locke’s own herbarium, his manuscript notes, journal and correspondence, it is established that Locke made a modest contribution to early modern botany. It is shown that Locke had close and ongoing relations with the (...) Bobarts, keepers of the Oxford Botanic Garden, and that Locke distributed seeds and plant parts to other botanists, seeds of which the progeny almost certainly ended up in the most important herbaria of the period. Furthermore, it is claimed that the depth of Locke’s interest in and practice of botany has a direct bearing on our understanding of his views on the correct method of natural philosophy and on the interpretation of his well known discussion of the nature of species in Book III of his Essay concerning human understanding. (shrink)

Some scientific categories seem to correspond to genuine features of the world and are indispensable for successful science in some domain; in short, they are natural kinds. This book gives a general account of what it is to be a natural kind and puts the account to work illuminating numerous specific examples.

The Empiricist or Lockean view says natural kinds do not exist objectively in nature but are practical categories reflecting use of words. The Modern, Ostensive view says they do exist, and one can refer to such a kind by ostention and recursion, assuming his designation of it is related causally to the kind itself. However, this leads to a problem: Kinds are abstract repeatables, and it seems impossible that abstractions could have causal force. In defence of the Modern view, I (...) suggest we can think of kinds as — or as like — ecological niches existing in nature, which are causally effective by virtue of the fact that they predictively determine (some) properties of the things that happen to occupy them. (shrink)

The Philosophical search for Natural Kinds is motivated by the hope of finding ontological categories that are independent of our interests. Other requirements, of varying importance, are commonly made of kinds that claim to be natural. But no such categories are to be found. Virtually any kind can be termed ‘natural’ relative to some set of interests and epistemic priorities. Science determines those priorities at any particular stage of its progress, and what kinds are most ‘natural’ in that sense is (...) always a real and lively scientific question. The general philosophical problem of scientific realism is also real; but between the scientific and the metaphysical, the ‘Problem of Natural Kinds’ sits otiose. (shrink)

This paper considers Kant's understanding of conceptual representation in light of his view of geometry.

This paper studies Robert Boyle's account of kinds and classification. A number of commentators have argued that, for Boyle, classifications are inevitably the product of conventions. Others have challenged this reading, arguing that, according to Boyle, the corpuscular makeup of bodies gives rise to hard-edged natural kinds and classes. We argue that Boyle's position is more complicated than the available realist and conventionalist readings acknowledge. We argue that, according to Boyle, the individuation of kinds was to some degree the result (...) of convention. At the same time, however, Boyle held that our classificatory practices are subject to constraints. We identify some of these constraints by turning to Boyle's discussion of the late scholastic debate about the plurality of forms, in particular the contributions of Jacopo Zabarella and Daniel Sennert. In this way, we clarify how Boyle strikes a balance between realist and conventionalist elements in his treatment of kinds. (shrink)

According to the standard narrative, natural kind is a technical notion that was introduced by John Stuart Mill in the 1840s and the recent craze for natural kinds, launched by Putnam and Kripke, is a continuation of that tradition. I argue that the standard narrative is mistaken. The Millian tradition of kinds was not particularly influential in the 20th-century, and the Putnam-Kripke revolution did not clearly engage with even the remnants that were left of it. The presently active tradition of (...) natural kinds is less than half a century old. Recognizing this might help us better appreciate both Mill and natural kinds. (shrink)

This essay is an analysis of the theory of human rights based on the writings of Thomas Aquinas, with special reference to the Summa Theologiae. The difference between a jus naturale found in Aquinas and the theory of human rights developed by the sixteenth century scholastic philosophers is articulated. The distinction between objective natural rights—“what is right”—and subjective natural rights—“a right”—is discussed noting that Aquinas held the former position and that later scholastic philosophers beginning with the Salamanca School of the (...) Second Scholasticism developed the latter position. The subjective theory of rights evolved into the modern and contemporary account of individual human rights. The essay ends with an argument suggesting that Aquinas’s theory of objective human rights can serve as the ontological foundation for a robust theory of both positive and negative subjective natural rights. (shrink)

In Putnam's theory of reference, an historical component and an indexical one both play some part in establishing the extension of terms, although in “The meaning of ‘meaning’” it is not altogether clear just how important he believes the historical element to be. He seems to be much more interested in its indexical component, which he believes plays more or less the same role in his theory as rigidity does in Krip-ke's. In this paper, I will look more closely at (...) these two elements and see what sorts of roles they could play in a theory like Putnam's. A theory of the extensions of general terms will emerge which differs from Putnam's in some important respects. It does, however, have some similarity with a recently published theory of Matthen's, but the arguments are different. I will also outline a theory of essences and kinds, which is based on this modified version. (shrink)

The aim of this article is to illustrate how a belief in the existence of kinds may be justified for the particular case of natural kinds: particularly noteworthy in this respect is the weight borne by scientific natural kinds (e.g., physical, chemical, and biological kinds) in (i) inductive arguments; (ii) the laws of nature; and (iii) causal explanations. It is argued that biological taxa are properly viewed as kinds as well, despite the fact that they have been by some alleged (...) to be individuals. Since it turns out that the arguments associated with the standard Kripke/Putnam semantics for natural kind terms only establish the non-descriptiveness of natural kind terms and not their rigidity, the door is open to analyze these terms as denoting traditional predicate-extensions. Finally, special issues raised by physical and chemical kinds are considered briefly, in particular impurities, isotopes and the threat of incommensurability. (shrink)

We often legitimately ascribe reality both to social and to natural kinds. But the bases for these ascriptions are not entirely the same. In both cases, reality is typically determined by what characterizations of causal factors are indispensable to adequate explanation. Nonetheless, a psychological role as part of an identity that instances embrace is sometimes, distinctively, a condition for ascribing reality to a social kind. Although such assessments of reality can be construed as employing a standard of causal activity shared (...) with natural science, they reveal a distinctive moral dimension in the bases for ascribing reality to social kinds. (shrink)

What are biological species? Aristotelians and Lockeans agree that they are natural kinds; but, evolutionary theory shows that neither traditional philosophical approach is truly adequate. Recently, Michael Ghiselin and David Hull have argued that species are individuals. This claim is shown to be against the spirit of much modern biology. It is concluded that species are natural kinds of a sort, and that any 'objectivity' they possess comes from their being at the focus of a consilience of inductions.

It has been suggested that the theory of reference advanced by Kripke and Putnam implies, or presupposes, an aristotelian vision of natural kinds and essences. I argue that what is in fact established is that there are degrees of naturalness among kinds. A parallel argument shows that there are degrees of naturalness among individuals. A subsidiary theme of the paper is that the definition of "natural kind term" as "rigid designator of a natural kind" is mistaken. Names and natural kind (...) terms are defined by ostension to a spatiotemporal part of what they ostend. This helps us understand why 'Hesperus' and 'Phosphorus' are cognitively non-equivalent. (shrink)

El objetivo del presente trabajo es, por un lado, reivindicar la importancia e influencia del enfoque de Locke para la discusión sobre los géneros naturales y, por otro, mostrar cómo su visión y aportaciones en torno al sistema de clasificación natural resultan de gran utilidad para entender en profundidad la compleja geografía del debate contemporáneo sobre estos géneros. En particular, ofrecemos una interpretación según la cual las concepciones de género natural se comprenden como críticas realistas a la posición que sostiene (...) Locke y mostramos cómo una importante tensión que aflora en la propuesta de Locke reaparece en el actual debate sobre los géneros naturales. (shrink)

ABSTRACT Post-truth, understood as a turn from collective sense and judgment to nonpublic forms of epistemic justification, is a distinctly rhetorical problem. This article offers, in response, a theorization of knowledge making as the means by which affective and material impingements upon bodies become publicly legible and rhetorically available. For this, the author turns, perhaps unexpectedly, to John Locke. Locke’s works offer the foundations of an empirical theory of rhetoric that embraces the sensible realm not as a conduit to reality (...) but as a space where social connection becomes possible. Locke engages this realm through natural historical inquiry. Tracing this inquiry to his commonplacing practices, the author presents the rhetorical-dialectical topics as a basis for the shared sense and judgment that he pursued and that post-truth demands. The topics, this article argues, guide and enlarge the senses, forming objects of knowledge with which to sustain public life—objects about which plural truths are possible. (shrink)

In recent years both philosophers and scientists have asked whether or not our current kinds of mental disorder—e.g., schizophrenia, depression, bipolar disorder—are natural kinds; and, moreover, whether or not the search for natural kinds of mental disorder is a realistic desideratum for psychiatry. In this dissertation I clarify the sense in which a kind can be said to be “natural” or “real” and argue that, despite a few notable exceptions, kinds of mental disorder cannot be considered natural kinds. Furthermore, I (...) contend that psychopathological phenomena do not cluster together into kinds in the way that paradigmatic natural kinds (e.g., chemical kinds and species) do; and, in light of this fact, I conclude that the normative ideal of natural classification—i.e. classifying real or natural kinds—is not appropriate as a general strategy for psychiatry. In the conclusion to this dissertation I propose an alternative way forward. Rather than assuming a priori that psychopathological phenomena cluster together into kinds, a more tractable and theoretically promising approach would be to first explain how particular kinds of experiences and behaviours—e.g, hallucinations, delusions, disorganized thinking, mania, low mood, etc.—are produced. (shrink)